Components included in electronic devices include heat-generating components that generate heat. An increase in temperature of the electronic devices due to heat generated by the heat-generating components causes an operational abnormality in the electronic devices. Accordingly, a cooling mechanism is arranged in the conventional electronic devices. Cooling mechanisms of these electronic devices includes a liquid cooling method for circulating a liquid whose temperature is lower than that of the heat-generating components to be cooled and an air cooling method for cooling the components to be cooled by bringing cooling air into contact with them.
In the conventional air cooling method, in a casing (or a chassis) that includes a circuit boards having mounted thereon the heat-generating components, an opening is arranged at a position close to the heat-generating component and cooling air is introduced from the opening. This is because the components to be cooled are intensively cooled by locally introducing the cooling air in the vicinity of the components to be cooled.
In the conventional technology, it is assumed that the cooling air makes contact from the front with respect to the surface of the casing that includes a board having mounted thereon the heat-generating component, and thus an air intake opening is arranged at the center of the heat-generating component to be cooled.
Furthermore, the conventional technology also uses complex electronic devices in which a plurality of electronic devices are connected with each other and share the cooling air supplied to or discharged from each of the electronic devices.
Patent Literature 1: Japanese Laid-open Patent Publication No. 08-46381
Patent Literature 2: Japanese Laid-open Patent Publication No. 2006-108601
Patent Literature 3: Japanese Laid-open Patent Publication No. 2008-43047
Patent Literature 4: Japanese Laid-open Patent Publication No. 02-304999
Patent Literature 5: Japanese Laid-open Patent Publication No. 2004-235258
Patent Literature 6: Japanese Laid-open Patent Publication No. 2007-188420
However, the cooling air is not always supplied from the front with respect to the wall of the casing of the electronic device. With the conventional cooling structure that has an opening at the center of the electronic component, if the cooling air is supplied from a direction that is oblique with respect to the wall of the casing of the electronic device, the cooling air enters from the opening oblique with respect to the wall. If the cooling air enters obliquely from the opening, the cooling air effectively makes contact in the region on the downstream side of the heat-generating component to be cooled; however, the cooling air does not sufficiently make contact in the region on the upstream side. Accordingly, the cooling of the heat-generating component varies, thus reducing the cooling efficiency.
As described above, in the conventional technology, there is a problem in that the cooling efficiency is reduced when the cooling air is supplied from a direction that is oblique with respect to the wall of the casing of the electronic device.